<p>I would advise to take as many tests as you can fit in (both ACT and SAT), but I agree with ognopgod that you should see where you stand with ACT math. Older D struggled with the trickiness of SAT math. Her grade on the ACT was considerably higher, because the answers were more straight forward and she was able to plow forward and do very well. For younger D, her math scores were fairly equivalent on both the SAT and ACT (610). She got fewer wrong on the ACT (it wasn’t tricky), but she was unable to finish the test on time and so had a lot of random guess at the end of the test.</p>
<p>If it seems you can do better on the ACT math than on the SAT math, I would do all my math practice using the ACT format, but I would still take the SAT again, because you never know if a section will go up even without practice. Both D’s had random jumps on both tests (in all sections–sometimes going up 80 points or so), so I think it’s always worth the effort. If your scores do not improve over prior scores, just don’t send them.</p>